Portable punch press



Sept. 16, 1958 A. scHoLlN 2,351,838

PORTABLE PUNCH PRESS Filed Sept. 22, 1955 5 Sheets-Sheet 1 5 x m i2 66are! ,fic/oZziz Sept. 16. 1 58 A. SCHOLIN 2,851,888

PORTABLE PUNCH PRESS Filed Sept. 22. 1953 5 Sheets-Sheet 2 Sept. 16,1958 A, g iZExIQLEN $553,838

PORTABLE PUNCH: mass Filed Sept. 22, 1953 5 Sheet M-Sheet 4 PORTABLEPUNCH PRESS 5 Sheets-Sheet 5 Filed Sept. 22, 1953 United States PatentPORTABLE PUNCH PRESS Axel Scholin, Chicago, in.

Application September 22, 1953, Serial No. 381,617

4 Claims. (CI. 74-38) The present invention relates to a portable punchpress particularly designed for punching metal sheets.

The punch press comprises a frame having a fixed head and a movableplunger interconnected to the head by means of a pair of toggle links. Acrank operated by an electric motor mounted on the frame operates a pairof horizontal arms connected at one end to one of the toggle links. Eachof the horizontal-arms has a slot engaging the pin of a crank and isfree to idle until a trig ger-operated lever system is manually operatedto move a latch member into engagement with the horizontal arms toarrest movement of the crank pin in the slot, at which time the arms areeffective to rock the toggle links and raise and lower the plunger.

It is an object of this invention to provide a punch press with a handleto facilitate carrying it from place to another and another handlecooperating with the carrying handle to facilitate positioning itproperly with respect to the work material.

Another object is to provide a trigger adjacent the carrying handle'tofacilitate control of the punching operation when the motor is running.

Other objects of the invention and the various advantages andcharacteristics of the present portable punch press will be apparentfrom a consideration of the following detailed description, taken inconjunction with the accompanying drawings showing a preferredillustrative embodiment of the invention, in which:

Fig. 1 is an elevational view, taken from the right hand side, showing apunch press embodying the invention;

Fig. 2 is a fragmentary elevational view of the left hand side of thepunch press, looking in the directions of the arrows 2-2 in Fig. 3;

Fig. 3 is an end elevational view, taken from the rear of the punchpress looking in the direction of the arrows 3-3 of Fig. 2;

Fig; 4 is a fragmentary vertical sectional view of the punch pressshowing the horizontal arms and the trig ger controlled mechanism foroperating the latch member to prevent the horizontal arm from idlingrelative to the crank pin;

Fig. 5 is a detail perspective view of the latch member;

Fig. 6'isa front elevational view of the punch press, taken along theline 6-6 of Fig. 4;

Fig. 7 is a transverse sectional view, taken along the line 7-7 of Fig.6;

Fig. 8 is a fragmentary side elevational view showing one of thebearings for the shafts of the various gears;

Fig. 9 is a cross sectional view, taken along the line 9-9 of Fig. 8; i

Fig. l() is a fragmentary elevational view of the operating mechanismwiththe frame and motor omitted;

Fig. 1 l is a view similar to Fig. 10, showing the mechanism with thecrank pin in two different positions, one position being shown in dottedlines; and

Fig. 12 is a detail perspective view of the yoke operated by thetriggerto move the latch member into latching en- 2,851,888 atented Sept. 16,1958 Referring to the drawings, the punch press comprises 7 a frame 10having a base portion 11 provided with a flat bottom 12 so that it maystand upright on any suitable flat supporting surface and a bed 13 onwhich die block 14 is secured by a plurality of bolts 15. A suitable die16 may be held in the die block in any suitable manner, as by a setscrew 17. The die 16 is provided with a vertical bore 13 which isaligned with a larger bore 19 extending through the base portion of thepunch press. Although the die 16 is for punching holes through a sheetof metal it will be understood that different types of dies suitable forother operations, such as stamping, forming, or shearing, may besubstituted for the die 16.

A fixed intermediate frame portion 20, spaced above the bed 13cooperates therewith to form a throat 21 to permit entrance of the workpieces. A horizontal bore 22 provides a guide-way in which a stop member23 is slidably mounted. The stop member is held in any adjusted positionby a screw 24. The throat 21 is deeper than the insertion of the workrequires, and the stop member 23 effectively limits the depth to whichthe work piecesflm'ay be inserted. Frame portion 20 is provided with avertical bore 25 aligned with bores 18 and 19. A plunger 26', slidablymounted in bore 25, is provided with a recess 27 extending upwardly fromits lower edge. A punch pin 28, adapted to fit with die 16, is held inplace in the recess 27 by means of a set screw 29. A stripper member 30is pivotally mounted on the fixed portion 20 to swing back into throat21 and is provided with a spring 31 urging it outwardly.

The upper end of plunger 26 is pivotally secured to the lower end of atoggle link 32. The upper end of. link 32 is pivotally connected to thecentral portion of a bifurcated toggle link 33 which straddles it. Theupper end of toggle link 33 is pivotally secured to a bracket 34 fixedrelative to the top of frame 10. The top of frame 10 is provided with athreaded vertical bore 35 anda tubular sleeve 36 is threaded therein.Bracket 34 is provided with a stud 37 which extends through sleeve. 36and is secured in place by a nut 38 tightened against the top of thesleeve. The vertical position of sleeve 36 may be adjusted within alimited range to regulate the position of bracket 34 and thereby varythe stroke of plunger 26 which is determined by the vertical distancebetween the pivot at the upper end of toggle link 33 and the pivot atthe lower end of toggle link 32.

A pair of parallel horizontal arms 39 are held in spaced relationship byan intermediate bar 4% and each arm is pivotally connected at one end tothe lower end of toggle link 33. The portion of each arm 39 extendingbeyond the end of bar 40 is provided with a longitudinal'slot 41 and acrank pin 42 extends through both slots 41. The crank pin is mounted ona pair of crank arms 43 which are rotated by an electric motor 44 havinga motor shaft44.

- The motor is provided with a base 45 and is mounted on the rear offrame it) by means of a plurality of screws or bolts 45'.

A plate 46, secured to the rear edge of frame 10 by a plurality of bolts46 is provided with a pair of plates 47 extending rearwardly therefromin parallel spaced relationship. Plates 47 may be integral with plate 46or welded thereto. Plate 46 is provided with a large central opening 47'(Fig. 4) aligned with a corresponding opening in the frame 10 to permitarms 39 to pass therethrough. A plurality of spacing rods 48 extendtrans versely between opposite edge portions of the plates-47.

A roller 48' is rotatably mounted on the rod 48 adjacent the upper edgeof plates 47 for a purpose hereinafter described.

Each plate 47 is provided with a plurality of self-aligning bearingassemblies 49 aligned in opposite plates to support a plurality ofshafts 50 carrying a series of gears 51, the shafts 50 and gears 51comprising a reduction gear train for motor 44. The platesv 47 are notthick enough to provide suitable bearing support for the shafts 50, andtheir thickness is built up, as shown in Figs. 8 and 9, by annular disks52 secured on opposite sides of each plate 47 adjacent each hearing bymeans of screws 53. Each disk is provided with an outwardly dishedflange 54 having its inner surface rounded, and the periphery of thebearing alloy 55 is shaped to fit within the flanges 54. A pin or stud56, projecting from the bearing alloy, is positioned within a recess 57in the edge of plate 47 to prevent the bearing alloy from rotating inthe plane of the plate 47. The pin 56 fits in recess 57 loosely enoughto permit a slight movement transverse to the plane of the plate 47 andthe rounded outer end of the bearing alloy 55 in contact with therounded inner surface of flanges 54 'moves in the same direction topermit selfalignment of each bearing with its shaft.

A latch member 58 is mounted on crank pin 42 and moves therewith as thecrank arms 43 are rotated by the motor. As shown in Fig. 5, the latchmember comprises two parts 59, 60, each provided with a semicircularrecess 61 which fits around crank pin 42. The parts 59, 60 are securedtogether by bolts or screws 62. The latch portion 59 has a pair of legs63 and 64 adapted to straddle the end of the bar 40 secured between thearms 39. The leg 64 of the latch member is provided with a shoulder 65facing the end of bar 40. The underside of leg 63 engages the uppersurface of bar 40 to limit the lowermost position of legs 63 and 64 andto maintain the straddling relationship with the bar 40 while the motor44 is running.

Operation of motor 44 rotates the crank pin in a fixed orbit and thelatch member 58 is moved forwardly and rearwardly with the crank pin.The crank pin is freely rotatable in the recess 61 and the weight of thelegs 63 and 64 keep the leg 63 in engagement with the top of bar 40. Theroller 48' coacts with leg 63 to prevent the latch 58 from swingingupwardly by centrifugal force as the crank pin 42 starts its forwardmovement. Roller 48' engages the upper surface of leg 63 and holds itdown as the latch moves forwardly. The length of legs 63 and 64 issufficient to keep the bight portion between legs 63 and 64 fromstriking against the rear end of bar 40 and to prevent disengagement ofthe leg 63 from the top of bar 40 throughout the orbit of the crank pin.The crank pin 42 extends through the slots 41 and does not move thehorizontal arms 39 as long as the latch member isfree to reciprocaterelative to the bar 40.

Frame is provided with a rearwardly extending handle 66 adjacent itsupper edge. A trigger 67, pivoted to frame 10 below handle 66, asindicated at 68, has a finger piece 69 extending approximately parallelto the handle a short distance below it so that the handle and fingerpiece may be grasped in the operator's hand and a slight squeeze willlift the lever 70 on the opposite side of pivot 68. A lever 71 pivotedat its upper end to lever 70 is pivoted at its lower end to a horizontalrod 72 (Figs. 10 and 12).

A horizontally disposed yoke 73, positioned below latch member 58 has aforwardly extending tongue 74 pivotally mounted on rod 72 and its rearend is pivotally mounted on a rod 75 carried by the plates 47 (Fig. 4).The tongue 74 is directly below the lower arm 64 of latch member 58.When the trigger 67 is squeezed upwardly against handle 66 the lever 71lifts the front end of yoke 73 upwardly and tongue 74 moves latch member58 pivotally upwardly about crank pin 42 until the shoulder 65 isaligned with bar 40. As the orbit of crank pin 42 moves the latch memberforwardly shoulder 65 engages the rear end of bar 40 and moves arms 39forwardly.

The forward movement of arms 39 tends to straighten the toggle links 32and 33. Since the bracket 34 holds.

the upper end of toggle link 33 in fixed vertical position the link 32moves downwardly and carries plunger 26 with it to drive punch pin 28downwardly into the bore 18 of die 16 to punch a hole in a work piece,such as a metal strip or sheet, positioned on the die. As long as thesqueezing pressure against trigger 67 is maintained the punch pin willbe driven downwardly with each forward movement of the arms 39, and awork piece on die 16 may be moved between strokes to form a series ofholes in the work piece very rapidly. If the trigger is squeezed and thepressure is immediately released, the punch will operate once and thenthe arms 39 will resume their idling motion.

The punch press is provided with a pressure pad comprising a bracket 76secured to the upper surface of the intermediate fixed portion 20 of theframe by means of screws 77 and having a horizontal flange 78terminating adjacent the upper end of plunger 26. Toggle link 32 has onelower edge cut away, as indicated at 79, and a stud 80, slidably mountedin a longitudinal recess (not shown), has one end bearing against ablock 81 loosely positioned on flange 78. A compression spring 82encircling stud 80 between the block 81 and the edge of toggle link 32adjacent the stud exerts constant force against the block 81 to retainit in place. Spring 82 exerts force which raises the toggle link 32after termination of the downward motion and maintains the angle betweenlinks 32 and 33 shown in Fig. l. A leaf spring 83 is secured to frame 10by a screw 84 and engages the rear edge of toggle link 33 to preventoverthrow of arm 39 in the direction of the motor when the toggle hasbeen moved rearwardly by the upward movement of plunger 26.

Handle 66 is sufficient for carrying the punch press, but because it issometimes necessary to position the press with some degree of precisionI prefer to provide an auxiliary handle 85 which is secured to thebottom of frame 10 by any suitable means, such as screws 86. The handle85 in addition to facilitating the accurate positioning of the punchpress, also facilitates carrying it around because it permits the use oftwo hands for this purpose.

Although I have described a preferred embodiment of my invention inconsiderable detail, it will be understood that the description thereofis intended to be illustrative, rather than restrictive, as many detailsmay be modified or changed without departing from the spirit or scope ofthe invention. Accordingly, I do not desire to be restricted to theexact details of construction described.

I claim:

1. A portable punch press comprising a frame, a carrying handle, a motormounted on said frame, a pair of toggle links pivotally mounted on saidframe, a horizontally movable arm connected at one end to one of saidtoggle links, a crank operatively connected to said motor, a crank pinmounted eccentrically of said crank, said movable arm having alongitudinally extending slot fitting around said pin, said slot beinglong enough to permit said arm to idle during the complete rotation ofsaid crank, a latch member pivotally mounted on said crank pin andmovable therewith, a bar rigidly secured to said horizontal arm, saidlatch member having a pair of legs straddling said bar in a verticaldirection as said latch member is reciprocated by rotation of saidcrank, a trigger mounted on said frame, said trigger including a fingerpiece positioned adjacent said carrying handle and a lever operativelyengaged with said latch member, said lever being moved upwardly uponactuation of said finger piece to move said latch member into engagementwith said bar whereby said horizontal arm moves said toggle links toactuate a punch.

2. A portable punch press comprising a frame, a carrying handle on saidframe, a motor mounted on said frame, a crank rotated by said motor, acrank pin mounted eccentrically of said crank, a pair of toggle linksoperable to actuate punching mechanism, said toggle links being normallyheld in inactive position, an arm pivotally secured at one end to one ofsaid toggle links, operatively connected with said crank pin, a barsecured to said arm, a latching member mounted on said crank pin, and atrigger mounted on said frame, said trigger having a finger piecepositioned adjacent said carrying handle and operable to move said latchmember into engagement with said bar and thereby cause said arm to movesaid toggle links out of said inactive position.

3. A portable punch press comprising a frame having a fixed head, amovable plunger interconnected to said fixed head by means of a pair oftoggle links connected to said head and plunger respectively, ahorizontal arm connected to one of said toggle links, means forreciprocating said arm to actuate said toggle links to move said plungerdownwardly, said means including a crank arm, a latch member directlyconnected to said crank arm and reciprocable therewith, said arm beingprovided with a longitudinally extending slot into which said crank armextends and in which it is slidable to permit said horizontal arm toidle while said latch member is being reciprocated, a finger operatedtrigger operable to move said latch member into engagement with saidhorizontal arm and thereby translate movement of the latch member intoreciprocation of said arm to actuate said toggle links to move saidplunger and means for rotating said crank arm.

4. A portable punch press comprising a frame member including a fixedhead, a vertical plunger interconnected with said head by means oftoggle links, a horizontal arm connected to one of said links, said armhaving a longitudinal slot, a crank provided with a crank pin engagingsaid slot, means for rotating said crank, said arm idling while saidcrank is being rotated, a latch member mounted on said crank pin, and atrigger operated lever system manually operable to bring said latchmember into engagement with said arm to arrest movement of said crankpin in said slot, whereby subsequent movement of said crank pin iseffective to actuate said toggle links to reciprocate said plunger.

References Cited in the file of this patent UNITED STATES PATENTS1,434,060 Lautenschlager Oct. 31, 1922 1,650,411 Yates Nov. 22, 19271,838,582 Skillman Dec. 29, 1931 1,926,576 Beatty Sept. 12, 19332,189,742 Ruppert Feb. 6, 1940 2,562,044 Klocke July 24, 1951 2,576,328Allison Nov. 27, 1951 2,652,291 Magarian Sept. 15, 1953 FOREIGN PATENTS14,279 Great Britain June 25, 1904

